CHAPTER 2: MEASUREMENTS IN CHEMISTRY

Transcription

1 CHAPTER 2: MEASUREMENTS IN CHEMISTRY MULTIPLE CHOICE 1) The mathematical meaning associated with the metric system prefixes centi, milli, and micro is, respectively, a) 10 2, 10 4, and 10 6 c) 10 3, 10 6, and 10 9 b) 10 2, 10 3, and 10 6 d) 10 3, 10 9, and ANS: B PTS: 1 DIF: Easy KEY: Chemistry general chemistry metric system NOT: Section 2.2 2) In which of the following sequences are the metric system prefixes listed in order of decreasing size? a) kilo giga mega c) mega kilo micro b) milli nano micro d) pico kilo deci KEY: Chemistry general chemistry metric system NOT: Section 2.2 3) Which of the following is an incorrect pairing of terminology? a) kilogram - metric unit of mass b) milliliter - metric unit of volume c) meter - metric unit of length d) cubic centimeter - metric unit of length KEY: Chemistry general chemistry metric system NOT: Section 2.2 4) To what decimal position should a measurement be recorded if the smallest markings on the measurement scale are tenths of a centimeter? a) to the closest centimeter c) to the hundredths of a centimeter b) to the tenths of a centimeter d) to the thousandths of a centimeter KEY: Chemistry general chemistry measurements NOT: Section 2.4 5) In which one of the following measure numbers are all of the zeros significant? a) c) b) 3,300,000 d) KEY: Chemistry general chemistry significant figures NOT: Section 2.4 Testbank General, Organic, Biological Chemistry, 6 th edition 1

2 6) In which of the following pairs of measured numbers does each member of the pair contain the same number of significant figures? a) 10.3 and c) and b) and 80 d) and 960,000 KEY: Chemistry general chemistry significant figures NOT: Section 2.4 7) In which of the following cases is the given measurement correctly rounded to three significant figures? a) 479,000 becomes 479 c) becomes 38.0 b) becomes d) becomes 49,400 KEY: Chemistry general chemistry significant figures NOT: Section 2.5 8) Which of the following would involve an exact number? a) the length of a table c) the number of inches in a yard b) the mass of a bag of carrots d) the surface area of a quilt KEY: Chemistry general chemistry exact/inexact numbers NOT: Section 2.3 9) The measurement expressed in scientific notation becomes a) c) b) d) KEY: Chemistry general chemistry scientific notation NOT: Section ) What is the uncertainty associated with the measurement of 6.02 x 10 4? a) 100 c) 0.1 b) 10 d) 0.01 ANS: A PTS: 1 DIF: Moderate KEY: Chemistry general chemistry scientific notation NOT: Section ) The calculator answer obtained from multiplying the measurements and 6.57 is Given the operational rules governing significant figures, this answer a) is correct as written c) should be rounded to 424 b) should be rounded to d) could be written as KEY: Chemistry general chemistry significant figures mathematical operations NOT: Section 2.5 Testbank General, Organic, Biological Chemistry, 6 th edition 2

3 12) The correct answer obtained from adding the measurements 9.6, 4.79, and contains a) two significant figures c) four significant figures b) three significant figures d) five significant figures KEY: Chemistry general chemistry significant figures mathematical operations NOT: Section ) The correct answer obtained by dividing the measurement by the measurement is a) c) b) d) KEY: Chemistry general chemistry scientific notation mathematical operations NOT: Section ) According to dimensional analysis, which of the following is the correct setup for the problem "How many milligrams are there in 85 kilograms?" a) c) b) 85 d) 85 KEY: Chemistry general chemistry dimensional analysis NOT: Section ) How many conversion factors can be derived from the equality 60 seconds = 1 minute? a) two c) four b) three d) an unlimited number ANS: A PTS: 1 DIF: Easy KEY: Chemistry general chemistry conversion factors NOT: Section ) The density of an object is the ratio of its a) length to volume c) mass to volume b) mass to height d) length to mass KEY: Chemistry general chemistry density NOT: Section ) If object A weighs 6.0 grams and has a volume of 3.0 ml and object B weighs 9.0 grams and has a volume of 2.25 ml a) B is less dense than A. c) B is twice as dense as A. b) A and B have equal densities. d) B is four times as dense as A. Testbank General, Organic, Biological Chemistry, 6 th edition 3

4 KEY: Chemistry general chemistry density NOT: Section ) What is the mass, in grams, of 30.7 ml of a liquid if its density is 0.81 g/ml? a) 3.8 c) 4 b) 25 d) 249 KEY: Chemistry general chemistry density NOT: Section ) Which of the following comparisons of the size of a degree on the major temperature scales is correct? a) A Kelvin degree is larger than a Celsius degree. b) A Fahrenheit degree and a Celsius degree are equal in size. c) A Fahrenheit degree is larger than a Kelvin degree. d) A Celsius degree and a Kelvin degree are equal in size. KEY: Chemistry general chemistry temperature scales NOT: Section ) If the temperature of an object is 435 oc, what is the temperature on a Kelvin scale? a) 162 K c) 672 K b) 608 K d) 708 K ANS: D PTS: 1 DIF: Easy KEY: Chemistry general chemistry temperature scales NOT: Section ) In which of the following pairings of metric system prefix and power of ten is the pairing incorrect? a) kilo- and 10 3 b) micro- and 10 6 c) deci- and 10 1 ANS: D PTS: 1 DIF: Easy KEY: Chemistry general chemistry metric system NOT: Section ) In which of the following pairs of units is the first listed unit 1000 times larger than the second? a) milligram and nanogram b) liter and centiliter c) kilometer and megameter ANS: E PTS: 1 DIF: Moderate KEY: Chemistry general chemistry metric system NOT: Section 2.2 Testbank General, Organic, Biological Chemistry, 6 th edition 4

5 23) In which of the following sequences of measured numbers do all members of the sequence contain three significant figures? a) 3.03 and 3.30 and b) 78,000 and and 780 c) 30.0 and and 30,100 KEY: Chemistry general chemistry significant figures NOT: Section ) Which of the following digits in the measurement 654,300 seconds is an estimated digit? a) the last digit b) the next to last zero c) the three KEY: Chemistry general chemistry significant figures NOT: Section ) Which of the following statements concerning the measured number is correct? a) Only one of the zeros in the number is significant. b) Rounded off to two significant figures the number becomes c) Expressed in scientific notation the number becomes d) More than one correct response. e) No correct response. KEY: Chemistry general chemistry scientific notation; significant figures NOT: Section ) Which of the following mathematical expressions is correctly evaluated? a) b) = c) ANS: A PTS: 1 DIF: Moderate KEY: Chemistry general chemistry scientific notation NOT: Section 2.6 Testbank General, Organic, Biological Chemistry, 6 th edition 5

6 27) Which of the following measured numbers contains three significant figures and has a magnitude of less than one? a) b) c) KEY: Chemistry general chemistry scientific notation NOT: Section ) When expressed in scientific notation, the measured numbers 3200 and become, respectively, a) and b) and c) and KEY: Chemistry general chemistry scientific notation NOT: Section ) Which of the following measured numbers has an uncertainty of 0.01 associated with it? a) b) c) KEY: Chemistry general chemistry significant figures NOT: Section ) Which of the following statements concerning conversion factors is incorrect? a) English-to-English conversion factors come from defined relationships b) Metric-to-metric conversions come from measured relationships c) English-to-English conversion factors always contain exact numbers KEY: Chemistry general chemistry conversion factors NOT: Section 2.4 Testbank General, Organic, Biological Chemistry, 6 th edition 6

7 31) Which of the following conversion factors would limit a calculation to two significant figures? a) b) c) ANS: E PTS: 1 DIF: Moderate KEY: Chemistry general chemistry conversion factors NOT: Section ) Density can be used as a conversion factor to convert from a) mass to volume b) volume to mass c) metric unit mass to English unit mass KEY: Chemistry general chemistry density NOT: Section ) The density of table sugar is 1.59 g/ml. It is true that a) 2.00 g of table sugar occupies a volume of 1.17 ml. b) 3.00 g of table sugar occupies a volume of 1.97 ml. c) 5.00 g of table sugar occupies a volume of 3.14 ml. d) More than one correct response e) No correct response ANS: C PTS: 1 DIF: Difficult KEY: Chemistry general chemistry density NOT: Section ) Which of the following statements concerning the three major temperature scales is correct? a) Kelvin temperatures are always positive. b) The equation for converting from Celsius to Kelvin involves the number 273. c) The freezing point of water has a lower numerical value on the Kelvin scale than on the Fahrenheit scale. d) More than one correct response. e) No correct response. KEY: Chemistry general chemistry temperature scales NOT: Section 2.10 Testbank General, Organic, Biological Chemistry, 6 th edition 7

8 35) In which of the following pairs of temperature readings are the two members of the pair equivalent to each other? a) 32 F and 273 K b) 0 C and 373 K c) 0 C and 40 F ANS: A PTS: 1 DIF: Moderate KEY: Chemistry general chemistry temperature scales NOT: Section ) Statements: (1) The meaning of a metric system prefix is independent of the base unit it modifies. (2) Trailing zeros at the end of a measured number are never significant. (3) The answer to the problem 10 5 /10-3 is KEY: Chemistry general chemistry metric system; scientific notation; significant figures NOT: Section 2.2 Section 2.4 Section ) Statements: (1) In outer space, an astronaut may be weightless but never massless. (2) The metric system prefixes milli and micro differ in mathematical meaning by a factor of (3) The addition of 273 to a Fahrenheit temperature reading will convert it to a Kelvin temperature reading. KEY: Chemistry general chemistry metric system; temperature scales NOT: Section 2.10 Section ) Statements: (1) The measured number contains three significant figures. (2) The specific heat of water is higher than that of most other substances. (3) The equation 1 kg = 10 6 mg is a correct mathematical statement. Testbank General, Organic, Biological Chemistry, 6 th edition 8

9 KEY: Chemistry general chemistry metric system; significant figures; specific heat NOT: Section 2.10 Section 2.11 Section ) Statements: (1) The answer to the addition problem should have an uncertainty of hundredths. (2) The measurement 653,899, when rounded to five significant figures, becomes 65,390. (3) The higher the specific heat of a substance, the more its temperature will change when it absorbs a given amount of heat. KEY: Chemistry general chemistry significant figures; specific heat NOT: Section 2.11 Section ) Statements: (1) The conversion factor 10 3 m/1 km contains an unlimited number of significant figures. (2) Density may be used as a conversion factor to convert from mass to volume. (3) The equation 2.33 lb = 625 g is a correct mathematical statement. ANS: B PTS: 1 DIF: Easy KEY: Chemistry general chemistry conversion factors; density NOT: Section 2.7 Section 2.9 Testbank General, Organic, Biological Chemistry, 6 th edition 9

10 41) Statements: (1) A deciliter is equal to 100 milliliters. (2) The Kelvin temperature scale is closely related mathematically to the Celsius temperature scale. (3) Measurements cannot be exact because two estimated digits are always recorded as part of any measurement. KEY: Chemistry general chemistry metric system; significant figures; temperature scales NOT: Section 2.10 Section 2.2 Section ) Statements: (1) The answer to the calculation ( ) should contain three significant figures. (2) A meter is slightly larger than a yard, and a liter is slightly larger than a quart. (3) The numbers and both have a magnitude of less than one. KEY: Chemistry general chemistry metric system; scientific notation; significant figures mathematical operations NOT: Section 2.2 Section 2.5 Section ) Statements: (1) The size of the degree is the same on the Fahrenheit and Celsius temperature scales. (2) The measurement 62,300 has an uncertainty of 100. (3) The answer to the calculation should contain four significant figures. ANS: B PTS: 1 DIF: Difficult KEY: Chemistry general chemistry significant figures; temperature scales mathematical operations NOT: Section 2.10 Section 2.4 Section 2.5 Testbank General, Organic, Biological Chemistry, 6 th edition 10

11 44) Statements: (1) The measured numbers 244,000 and contain the same number of significant figures. (2) One cubic centimeter is equal to ten milliliters. (3) The conversion factor 1 in/2.54 cm, when used as written, would decrease unit size. KEY: Chemistry general chemistry conversion factors; metric system; significant figures NOT: Section 2.2 Section 2.4 Section 2.7 Testbank General, Organic, Biological Chemistry, 6 th edition 11